Well-drilling bit



Panarea nay a ieee UNrrEn sra'rns EPTENT FFM .ARCHER W'. OF FUILLER'JOIN,` CALIFORNIA, ASSIGNOR TO WILLIAM KAM- i HEBER, OF PLACENTIA, GALIFORNIA WELL-DRILLING BIT Application ama vMay 1e,

This invention hasl to dowith a well drill; ing bit and it is an object of the' invention to provide a simple, e'ective and economical tool of this character. 5 Hard cutting alloys or compounds have been developed and have come into extensive use in-the oil fields for facing the cutting parts of drills or bits. Tuhese hard facing materials are very expensive and are more or less difiicult to apply, and as afresult their practical use has been limited to simple dragtype bits wherein the 4facing material has been welded to the cutting edges of the teeth. The disk type of bit, that is the type'of bit having rotating disk cutters, has certain recognized advantages over other types and particularly over the drag type. However, the cutting edges in an ordinary disk bit are so -extensive as to make the use of high-grade hard facing too costly for practical use.

It is an object of this invention to provide a bit or drill of the disk type in which the disk cutters are proportioned so that they can be practically and economically iinished with hard acin material.

It is anot er object of this invention to provide a simple, practical and efectiveiarrangement of cutters or-disks whereby the greater portion of the cutting action is confined to the outer or eripheral portion of the cut.,

Another o ject of this invention is to provide a unique and improved reaming blade on a well drilling bit, the invention providing an arrangement whereby a drill collar or other part of the drilling string above the bit operates to hold the reaming blade in place.

The various objects and features of this invention'will be best and more fully understood from the following detailed description of a typical form and application of the invention,` throughout which description I refer to the accompanying drawings, `in which:

Fi 1 is a side elevation. of the bit provide 'by thisinvention showing it on afdrill collar. Fig. 2 is a. vertical sectional view of 1928. Serial No.E278,124.-.

ample, I have shown a'simple form of construction in which the invention is carried out with three disk cutters; one large cutter cutting from the periphery or outer portion of the bore to the central portion of the bore, and two smaller cutters cutting only at the outer portion of the bore.

In the drawings I illustrate the bit provided by this invention applied to a drill collar 10. In practice the bit may be connected in any suitable manner to the lower end of a string of drill pipe, or the like. The bit comprises, generally, a body 11 provided at its upper end with a tapered screw-threaded pin projection 12 to screw thread into the" drillv collar or other similar part. The body is providedv at its lower end with a plurality of spaced legs 13 which carry disk cutters. The legs 13 are spaced radially from the central longitudinal axis of the bit, and in the case yof a bit having three cutters the legs are spaced 120 degrees apart .sothat they are uniformly spaced.

In accordance with my present invention, disk cutters `are rotatably mounted on the legs so that-they project outwardly beyond the body 11 and operate to make a cut or bore of the desired diameter. The invention provides a single large cutter 2O on one of the legs 13 to cut at the bottom of the bore and from the outer portion of the bore inwardly to the center or middle portion 01E the bore, and it provides small cutters 21 on the other legs to cut only `on the bottom and'outer portion of the bore. v

' The cutters 20 and 21 may be of the ordinary type used in drills of this character; for. instance, they may be iat disks having their peripheral portions dressed or iinished to present cutting edges 22. Further, the disks may the bit shown` in 1. Iigu 3 isalower end/be mounted on the legs in any suitable manelevation of the bit showing arrangement and propcrtioning or' the 4cutters as provided by ner. In the drawings I have shown a stud. or projection '23 on the forward side of each leg. The stud projection forms a support for a bushing 24 on which the disk cutter is rotatably supported. A flange 25 is provided on the outer end of the bushing 24 for retaining the cutter on the bushing, while a key 26, or the like, operates to hold the bushing on the projection 23. Further, in practice a washer 27 is provided between the cutter and the forward side of the leg, as clearly illustrated in Fig. 4. The projection 23 provided on the leg may be integral with the leg, for instance formed on the leg or welded to it.

The large cutter 20 issupported by its leg 13 so that'it cuts to the same diameter as the small c'utters 21 and to the same depth as the small cutters 21 and extends inwardly to the central portion of the bore, for instance to a point at or close to the central longitudinal axis of the bore.` This large cutter 20 thus operates to aid the small cutters in cutting on the bottom and side of the bore and also cuts the central formation left uncut by the small cutters. The small cutters 21 may be considerably smaller in diameter than the large cutter 20 and may be supported by their legs 13 so that they aid the large cutter in cutting the bore to the desired diameter and in cutting on the bottom of the bore at the outer or peripheral portion.

In practice the legs may be designed to support the cutters at various angles so that they have the desired bite in the formation and so that they rotate in the desired manner as the drilling operation takes place. For purpose of example I have illustrated the large cutter and one of the small cutters mounted so that the outermost parts of their cutting edges 22 extend forward or ahead of the other arts, in other words the cutters are pitched orward. I have shown the other small cutter pitched in the opposite direction or rearwardly. If desired, the cutters may be further pitched, for instance they may be tilted or pitched so that their lowermost parts are advanced or ahead of the upper parts.

The present invention, through the arrangement and proportioning of parts above described and illustrated in the drawings, causes the drill to make a cut of agiven size with but one large disk cutter and two small ones, whereas the constructions and arrangements heretofore provided for bits of this character have required two or more large disk cutters. The invention thus provides a disk type of`bit having a comparatively small amount of cutting edge and thus permits-of the cutting ed es of the disks being faced with high-gra e hard facing material without making the cost of the bit excessive.

The reaming means provided by the inven- "D tion comprises-.encor more blades 30 arranged 'to project from thefbodyl 11. In the arrange- 'mentillustratedl have disclosed two ream.- 'I in blades 30located at ldiametrically opposite l-si es of thebody-11. In accordance with my invention, dove-tailed or inwardly divergent sockets 31 are formed in the sides of the body to extend downwardly from the upper end of the body. The blades 30 are made to correspond in cross section to the sockets 31 and to project the desired distance outwardly beyond the body. The blades are slid into place in the sockets from the upper end of the body. The projecting portions of the blades are linished or dressed to have cutting edges 33 as shown in the drawings. When the bit is ap plied to a drill collar 10 or other suitable operating member the drill collar seats against the upper end of the body 11 and thus oper- .ates to retain the blades 30 in the sockets. It will be understood, of course, that the cutting edges 33 of the reamer blades may be faced with hard facing material if desired.

The bit may be providedl .with means whereby circulation is supplied to the operating or cutting parts, for instance a central longitudinal circulation opening 40 may be provided through the body 11 to discharge at vthe lower end of the body between the cutters.

Having described only a typical preferred form of my invention, I do not wish to limit myself to the specilic details set forth, but Wish to reserve to myself any changes or variations that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

l. A well drilling bit including a body, a plurality of spaced legs onthe body, a large disk cutter mounted on one leg to cut on the bottom and to the side wall of the bore, and small disk cutters mounted on the other legs to cut on the bottom and to the side wall of I the bore.

2. A. well drilling bit including a body, a plurality of spaced legs on the body, a large disk cutter mounted on one leg to cut on the bottom and to the side wall of the bore, and small disk cutters mounted on the other legsto cut on the bottom and to the side wall of the bore, the axis of the large cutter being located above and inward of the axes of the mall cutters relative to the central axis of the it.

3. A well drilling bit including a body, a plurality of spaced legs on the body, a large inner disk cutter mounted on one leg to cut on the bottom and to the side wall of the bore, and small outer disk cutters mounted `on the kother legs -to cut on the bottom and to the side wall of the bore, the inner cutter and outer cutters being arranged in different angular positions. l

4. A well drilling bit including a body, a )plurality of uniformly spaced legs on the body, a large disk cutter mounted on one leg to cut on the bottom and to the side wall of the bore,4 andsmall disk cutters mounted on the other legs to cut on the bottom and to the side wall of the bore.l

5. A well drilling bit including a body, a plurality of spaced legs on thebody, a large disk cutter mounted on one leg to extend from the centralportion of the bore to the periphery of the bore,and small disk cutters mounted on the other legs to cut at the peripheral portion of the bore.

6. A Well drilling bit including a body, a plurality of spaced legs on the body, a largeI disk cutter mounted on one leg to cut at the bottom of the bore and to extend from the. central portion of the bore to the periphery of the bore, and small disk cutters mounted on the other legs to cut at the peripheral portion of the bore.

7. A well drilling bit including a body, a plurality of spa-ced legs on the body, a large disk cutter mounted on one leg to extend from the central portion of the bore to the periphery of the bore, and small disk cutters mount` ed on the other legs to eut at the bottom of the bore and the peripheral portion of the bore.

8. A well drilling bit including a body, a plurality of spaced legs on the body, a large disk cutter mounted on one leg to cut at the bottom of the bore and to extend from the central portion of the bore to the periphery of the bore, and small disk cutters mounted f" on the other legs to cut at the bottomof the bore and the peripheral portion of the bore.

9. A well drilling bit including a body, a

'35 plurality of spaced legs on the body, a large disk cutter mounted on one leg tolut on the bottom and to the side wall of thev \ore, and small disk cutters mounted on the other legs to cut on the bottom and to the side wall of 40 the bore, the large cutter being mounted 4to extend outwardly from the central axis o the bit and forward, in the direction of operation of the bit, and one of the small cutters being mounted to extend outward from the axis ofthe bit and rearward relative to the direction of operation of the bit.

10. A well drilling bit including a body, a plurality of spaced legs on the body, a large disk cutter mounted on one leg to cut at the bottom of the bore and to extend from the central portion of the bore to the periphery of the bore, and small disk cutters mounted on the other legs to cut at the bottom of the bore and the peripheral portion of the bore, the large cutter being mounted to extend outwardly relative to the central axis of the bit and forward in the direction of operation of the bit, and one of the small cutters being mounted to extend outward from the central axis of the bit and rearward relative to the direction of operation of the bit. a In witness that I claim the foregoing I have hereunto subscribed my name this 24th day -v oA'pril, 1928.

ARCHER W. KAMMERER. 

